Electrical conduit



r. D. slm-(Lola ELEcTRIAL cNDUIT Nov. 16 1926.

Filed Feb. A15'. 192s I7 bve? Lo ZM f @a4 $4 Patented` Nov. 16,# 1926.

UNITED .STAT-Eis PATENT oFFlpcE.

rnaNK D. sAvYLoB., on WHEELING, WEST VIRGINIA, AssIGNoR oF ONE-HALF ro` 'RUSSEL DART, or NEW Yom; N. Y.

Application filed February 13, '1923.` vSerial No. 618,825..

-i My invention relates Jto improvements in non-metallic iiexible conduits for electric conductors, and in the method of manufacturing the same. fi

The object o f my invention is to produce ^an eflicient conduit of the character named 'at a minimum cost, and to produce a paper string or cord which isv especially fitted and adapted for use as a helicalwoof or filling l in the manufacture of such conduits.

It is essentialthat such conduits should be able to maintaintheir cylindrical form under the usual lateral pressure to which they are subjected, and also when flexed to form curves and bends during the installation4 of the conduits for interior use in buildings. It is also importantvthat the wall of suchlconduits should be firm and strong in order to serve its purpose as an armor to protect the insulation of the enclosed conductor from abrasion and from other in-A juries from violence during transportation A in the process of installation. It is also necessary because of the market conditions and keen competition, that such articles be prodnced at a minimum cost. With these objects in view I have devised the conduit illustrated in the accompanying drawing in which Fig. l is a .perspective view of a conduit embodying my invention; Fig. 2\

is a cross sectionof the cord forming the helical member or Woof of the conduit.; Fig. 3 is a diagram illustrating the method of forming theY string or cord.

Referring to Fig. 3 of the drawing, 4 is a strip o f tissue paper approximately a half inch wide wound upon a suitable spool or 'I bobbin.y 5 is a cotton orother textile thread or string designed to form a core for the 40 finished 'string or cord. In the manufacture of the cord the thread 5 is fed through a bath of sizing contained in the trough 6, then into the V-sha c d former 7 together with the paper sti'1p 4, the latter being wrapped around the thread 5 by the action of the V-shaped former when the paper strip 4 and the thread 5 are drawn through the same by any. suitable means. The thread 5 becomes not .only thoroughly saturated .5G but coatedjwith the sizing, and the paper strip 4 becomes saturated with it by absorp- ,a hard 'and highly resilient cord. I am vthen drawn through any of the well known machines for twisting paper strips and forming paper cord. The sizing yis thereby squeezed into the pores and interstices of the' paper and the thread, thoroughly impregnating the .same so that they become practically a homogeneous substance, which When thoroughly dried forms awarev that paper cord has been treated with sizing and other stiifening compounds before my invention and that a thread has been enclosed'in the paper strip, and I make no claim to the same. The novelty of my invention resides in enclosing the thread while saturated andcoated with the fresh sizing in the porous paper strip andthereby insuring a complete impregnation of the finished cord with the sizing which cannot be accomplished merely by subjecting the finished papercord to an external bath of sizing. L

'In Fig. l Ihave shown a non-metallic exible condnitembodying lmy invention, combining a helical member or weftl 9 of paper cord made by the method hereinbefore described, and warp threads 10 of cotton or other suitable material wovenupon one of the familiar types of circular 85 loom adapted for the purpose of forming tubing of the charactery described. l

The conduit madeby my method possesses. a hard and firm walland yet is readily flexed without attening and is produced at comparatively low cost. v p

What I claim and desire to secure by Letters Patent is:

1. An article of manufacture consisting of a core of porous material saturated with 95 a glutinous substance, combinedwith a cover of porous material and a layer4 of glutinous substance interposed between said coreand its cover. i

2. Ina non-metallic .flexible conduit a '100,

helical member composed of a core of porous material saturated with a glutinous sub-V! stance, having a cover of porous materialk and a. layer of glutinous substance interposed between said core' and its cover, combined with longitudinal threads interwoven with y l the helical member.

3. The p rocess of manufacturing cord which consists first of subjecting a. porous core to a beth of glutinous substance, then vsaid core and its cover tightly together.

In testimony whereof I have hereunto set my lhand this eighth day of February, 1923. o

FRANK D. sAYLoR.. 

